Control element

ABSTRACT

This invention relates to a control element, for example a control element for a temperature controller and/or steam controller. The control element has a dial ( 11 ) with an opening ( 18 ) and a graphic plate ( 12 ) is located behind the dial ( 11 ). The graphic plate has a marking ( 19 ) which is at least partially aligned with the opening so that it is visible therethrough when the dial ( 11 ) is rotated relative to the graphic plate ( 12 ) within a first angular range.

This application is the U.S. National Phase application under 35 U.S.C.§ 371 of International Application No. PCT/EP2014/070466, filed on Sep.25, 2014, which claims the benefit of International Application No.13187470.3 filed on Oct. 7, 2013. These applications are herebyincorporated by reference herein.

FIELD OF THE INVENTION

The invention relates to a control element, for example a controlelement for a temperature controller and/or a steam controller.

BACKGROUND OF THE INVENTION

Steam irons typically have a temperature controller, such as athermostat, which includes a control element that allows a user to setthe operating temperature of the steam iron. A steam iron may have athermostat which includes a low temperature range in which steam is notproduced by the steam iron and a high temperature range in which steamis produced. As the temperature is further increased, the amount ofsteam that can be produced by the steam iron is also increased. Thecontrol element may be provided with several indicative markings thatinform a user of the characteristics of the steam iron when the dial isset to a particular position. For example, the amount of steam producedat a particular setting may be indicated by markings on, or adjacent to,the control element.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a control element whichsubstantially alleviates or overcomes the problems mentioned above.

The invention is defined by the independent claims. The dependent claimsdefine advantageous embodiments.

According to a first aspect of the present invention, there is provideda control element comprising a dial having an opening and a graphicplate located behind the dial, the graphic plate having a marking whichis at least partially aligned with the opening so that it is visibletherethrough when the dial is rotated relative to the graphic platewithin a first angular range.

Therefore, the opening and the marking can combine to form an indicatorduring rotation of the dial within the first angular range. That is, theamount of the marking visible through the window can inform a user of acharacteristic associated with the position of the control element. Forexample, the opening and marking may be used to indicate that thecontrol element is positioned within an operating range (correspondingto the first angular range of the dial) which is associated with aparticular characteristic, for example the operating temperature of adevice. The marking and opening form a simple and effective indicatorthat can quickly and simply be interpreted by a user.

The graphic plate may be rotatably mounted and the control element maycomprise engagement means operable to cause the dial and the graphicplate to cooperate so that they rotate together when the dial is rotatedwithin a second angular range, thereby preventing alignment of themarking on the graphic plate with the opening in the second angularrange so that the marking is not visible through the opening in thesecond angular range. In this way, the engagement means can be arrangedso that the position of the graphic plate is changed to preventalignment between the marking and the opening in rotational positions inwhich the alignment is not required or may be misleading. At the sametime, the opening and the marking have the appropriate size and positionso that they are aligned when the dial is within the first angular rangeand alignment is desired to form the indicator described above. Therotational movement of the graphic plate caused by the engagement meansprevents inaccurate and undesired alignment between the opening and themarking.

The engagement means may comprise a protrusion and a catch, theprotrusion being arranged to abut the catch when the dial is within thesecond angular range so that the graphic plate rotates together with thedial. Therefore, as the dial is rotated into the second angular rangethe protrusion will abut the catch and rotate the graphic plate togetherwith the dial, preventing alignment between the opening and the marking.Meanwhile, during rotation outside of the second angular range theprotrusion and catch are not engaged so that the graphic plate canrotate independently of the dial.

In one example, the protrusion extends from the dial and the catch isformed on the graphic plate.

The engagement means may be operable to rotate the graphic plate betweena home position, which is a position occupied by the graphic plate whenthe dial is rotated within the first angular range, and an end positionduring rotation of the dial within the second angular range.

The control element may comprise biasing means to bias the graphic platetowards the home position. In this way, when the dial is outside of thesecond angular range, and the engagement means is not engaged, thegraphic plate will return to the home position. Moreover, duringrotation of the dial within the second angular range the biasing meansmay act against the engagement means to keep the catch and protrusion incontact and thereby define the position of the graphic plate.

The biasing means may comprise an inclined cam surface and a resilientmember arranged to push against the inclined cam surface.

The inclined cam surface can be arranged such that the biasing meansacts in an opposite direction to the engagement means, so that duringrotation of the dial within the second angular range the biasing meansacts against the engagement means. As the graphic plate is rotated theinclined cam surface will compress the resilient member which providesan opposing force. Therefore, when the engagement means is disengagedfrom the graphic plate the resultant force on the graphic plate, causedby the resilient member pushing against the inclined cam surface, willcause the graphic plate to rotate towards the home position.

The control element may further comprise a second engagement meansoperable to engage the graphic plate when the graphic plate is in thehome position and when the graphic plate has been rotated to the endposition. Therefore, the second engagement means provides limits to therotation of the graphic plate. The graphic plate is only able to rotatebetween the home position and the end position and this defines thesecond angular range.

The second engagement means may comprise a recess in the graphic plateand a fixed pin that extends into the recess, the pin engaging with afirst end of the recess when the graphic plate is rotated to the homeposition and a second end of the recess when the graphic plate isrotated to the end position. Therefore, the separation between the firstand second ends of the recess defines the second angular range in whichthe graphic plate is able to rotate together with the dial. The firstand second ends of the recess will move and engage with the pin at thelimits of the rotation of the graphic plate.

According to a second aspect of the invention, there is provided atemperature controller comprising the control element described above.The temperature controller may be a thermostat.

According to a third aspect of the invention, there is provided a steamcontroller comprising the control element described above.

According to a further aspect of the invention, there is provided adevice comprising the temperature controller and/or the steam controllerdescribed above. According to another aspect of the invention, there isprovided a steam iron comprising the temperature controller and/or thesteam controller described above.

Therefore, the position of the dial may determine the operatingtemperature and/or the amount of steam being produced in a device, suchas a steam iron. The position of the dial can directly control thetemperature controller and/or the steam controller so that the user canaccurately control the device and the window and the marking form anindicator to inform the user of the operating temperature and/or theamount of steam being generated by the device when the dial is in thatposition.

These and other aspects of the invention will be apparent from andelucidated with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described, by way of example only, withreference to the accompanying drawings, in which:

FIG. 1 shows a control element for a temperature controller;

FIG. 2a shows a control element of a first embodiment of the invention,the control element having a window and a marking that form an indicatoraccording to the invention;

FIG. 2b shows the control element of FIG. 2a rotated to a minimumposition;

FIG. 3 shows a cut-away view of a control element of a second embodimentaccording to the invention;

FIG. 4a shows a schematic view of the control element of FIG. 3, in aminimum position;

FIG. 4b shows a schematic view of the control element of FIG. 3, in anintermediate position;

FIG. 4c shows a schematic view of the control element of FIG. 3, in amaximum position;

FIG. 5a shows a top perspective view of the graphic plate of the controlelement of FIGS. 3 to 4 c;

FIG. 5b shows a bottom perspective view of the graphic plate of thecontrol element of FIGS. 3 to 4 c;

FIG. 6a shows the control element of FIGS. 3 to 4 c, in a minimumposition;

FIG. 6b shows the control element of FIGS. 3 to 4 c, in an intermediateposition; and,

FIG. 6c shows the control element of FIGS. 3 to 4 c in a maximumposition.

DETAILED DESCRIPTION OF THE EMBODIMENTS

A thermostat for a steam iron has a spindle which is connected to acontrol element, such as a rotatable dial. Rotation of the dial sets thetemperature of a soleplate of the steam iron, for example by controllingthe power supplied to the heater or some other variable. In some steamirons, the temperature of the soleplate determines the amount of steamthat can be produced without water leakage from the soleplate. Steam isnot produced until the temperature of the thermostat is set at a certaintemperature (e.g. 100 degrees Celsius) and the soleplate has reachedthat temperature. Beyond that temperature the rate at which steam isproduced, and the pressure of the steam in the steam iron, can beincreased as the temperature is increased. In other examples, thecontrol element may be directly connected to a steam controller suchthat rotation of the dial directly controls the amount of steam that isproduced by the steam iron. In one example, the control element may beconnected to both a temperature controller and a steam controller, sothat rotation of the control dial sets the operating temperature andsteam rate of the steam iron. In another example, the control elementmay be connected to a simple temperature controller, for example thecontrol element may directly control the current supplied to a heater.

FIG. 1 shows an example control element 100 for a steam iron. Thecontrol element 100 is attached to both a temperature controller and asteam controller so that rotation of a dial 102 of the control element100 controls the temperature of the soleplate and the amount of steamproduced by the steam iron.

As shown, the dial 102 has labels on an outer surface and a pointer 104disposed adjacent to the dial 102 which indicates different positions ofthe dial 102. The labels on the dial 102 relate to both the temperatureof the soleplate and the amount of steam being generated, as explainedbelow.

The dial 102 can be rotated between a minimum position and a maximumposition, which are indicated by the pointer 104 being aligned with theminimum and maximum labels 106, 107 shown on the dial 102. When theminimum label 106 is aligned with the pointer 104 the control element isin a minimum position and the temperature of the soleplate is at aminimum (or zero) value. When the maximum label 107 is aligned with thepointer 104 the control element is in a maximum position and thesoleplate will be heated to its maximum operational temperature. Anyrotational position which is intermediate of the minimum and maximumlabels 106, 107 results in some intermediate soleplate temperature. Thedial also includes labels that indicate the appropriate temperaturesetting for different materials that are being ironed. As shown in FIG.1, the dial 102 includes a one-dot label 112, a two-dot label 113 and athree-dot label 114 that correspond with soleplate temperatures suitablefor silk, wool and cotton/linen respectively. The ‘dot markings’ arewidely recognized in the industry and are commonly printed on clothinglabels. It will be appreciated that, due to the dial 102 being connectedto a controller, from the minimum position shown in FIG. 1 the dial 102can only be rotated in one direction, in this example a clockwisedirection. Similarly, when the dial 102 is set to the maximum position,the dial 102 can only be rotated in an anti-clockwise direction. Inother words, the dial 102 can only be rotated in the larger angularregion between the minimum and maximum positions, and cannot be rotatedinto the smaller angular region.

In the example shown in FIG. 1, the dial 102 also includes markings 109that indicate the amount of steam being produced by the steam iron. Themarkings 109 are formed of an arcuate band which includes a no-steamregion 110 and a steam region 111. When the dial 102 is rotated suchthat the no-steam region 110 is aligned with the pointer 104 the steamiron will not produce steam, and when the dial 102 is rotated such thatthe steam region 111 is aligned with the pointer 104 the steam iron willproduce steam. As the dial 102 is rotated towards the maximum label 107within the steam region 111 an increasing amount of steam will beproduced. An intermediate steam position is defined where the joinbetween the no-steam region 110 and the steam region 111 is aligned withthe pointer 104. The join in the steam markings 109 can be considered anintermediate steam label 105 and this position defines the change fromno-steam to steam as the dial 102 is rotated towards the maximum label107.

Any rotation of the dial between the minimum position and theintermediate steam position indicates to the user that steam should notbe generated, and any rotation beyond the intermediate steam positionindicates to the user that an increasing amount of steam can begenerated up until the pointer 104 is aligned with the maximum label107.

In the example shown in FIG. 1, the two-dot label 113, which correspondsto an appropriate soleplate temperature for woolen fabrics, is alignedwith the intermediate steam label 105. However, this alignment isoptional and the two-dot label 113 may be positioned elsewhere on thedial 102, depending on the arrangement of the temperature and steamcontrollers being controlled by the control element 100.

However, the labels and markings 105, 106, 107, 109, 110, 111, 112, 113,114 on a dial 102, such as that shown in FIG. 1, are unclear and it isdifficult for a user to quickly and accurately determine the amount ofheat and/or steam that will, or should, be produced when the dial 102 isin a particular position. This is an important consideration when usingthe steam iron as excess heat or steam can cause damage to some fabrics.Therefore, it is desirable to provide a control element that moreclearly and accurately displays the amount of heat and steam that may beproduced when the dial is rotated to particular positions.

FIG. 2a shows a first embodiment of the invention. In particular, FIG.2a shows a dial 2 that includes a window 8 through which one or moremarkings 9 can be viewed as the dial 2 is rotated into differentpositions. In this example, the window 8 is configured to allow a userto view a marking 9 on a surface behind the dial 2 and the marking 9 andwindow 8 are configured such that the amount of the window 8 occupied bythe marking 9 informs the user of the amount of steam that will beproduced at that particular dial position. The marking 9 behind the dial8 may be provided on a graphic plate or surface (not shown in FIG. 2a )positioned behind the dial 2.

Similarly to the example described with reference to FIG. 1, the dial 2has minimum and maximum labels 6,7 that indicate minimum and maximumpositions of the dial 2, and also an intermediate temperature label 3,represented by the two-dot label. An intermediate steam position may beindicated by an intermediate steam label 5 which, in this example, isaligned with the intermediate temperature label 3. For the purposes ofclarity in the drawings, the intermediate steam label 5 is shown as aline. However, as will become apparent hereinafter, when the dial 2 isrotated such that the pointer 4 is aligned with a first end 29 of thewindow 8, the dial is aligned with the intermediate steam position andtherefore the intermediate steam label 5 on the dial 2 is optional. Itwill be appreciated that, due to the dial 2 being connected to acontroller, from the minimum position the dial 2 can only be rotated inone direction, in this example a clockwise direction. Similarly, whenthe dial 2 is set to the maximum position, the dial 2 can only berotated in an anti-clockwise direction. In other words, the dial 2 canonly be rotated in the larger angular region between the minimum andmaximum positions, and cannot be rotated into the smaller angularregion. When the dial 2 is rotated so that the pointer 4 is aligned tothe intermediate steam label 5 the beginning of the marking 9 will bevisible at one end of the window 8. As the dial 2 is rotated towards themaximum position more of the marking 9 will be visible in the window 8until the marking 9 occupies the entire window 8 when the maximum label7 is aligned with the pointer 4, indicating maximum steam rate for thedevice.

Therefore, the marking 9 and the window 8 combine to provide anindicator that informs the user of the amount of steam that the steamiron will produce at that particular position of the dial 2. A user isquickly and easily able to view how much of the window 8 is occupied bythe marking 9 and thereby infer how much steam is going to be produced.The user does not need to ascertain which part of the marking 9 isaligned with the indicator 4 in order to determine how much steam willbe produced as the proportion of the window 8 occupied by the marking 9quickly communicates this information to the user.

In the example shown in FIG. 2a the dial 2 is set to a position wherethe pointer 4 is between the intermediate steam label 5 and the maximumlabel 7 so that roughly half of the window 8 is occupied by the marking9 on the surface behind the dial 2. Therefore, the user is quickly andeasily informed that the steam iron is operating at roughly half of themaximum steam rate.

In the example shown in FIG. 2a the marking 9 comprises a single band ofcolor that is aligned with the window 8 during a part of the rotation ofthe dial 2 the first angular range. However, it will be appreciated thatthe marking 9 may comprise one or more shapes or symbols that can bealigned with the window 8, and the window 8 may comprise one or moreopenings that allow the marking 9 to be visible through the dial 2 whenthe dial 2 is rotated within the first angular range. Alternatively, themarking 9 may comprise different shades of color. In this example, thefirst angular range extends between the intermediate steam position(indicated by the pointer 4 being aligned with the intermediate steamlabel 5) and the maximum position (indicated by the pointer 4 beingaligned with the maximum label 7) of the dial 2.

It is preferable to maximize the amount of the rotation of the dial 2 sothat the size of the marking 9 and window 8 can be increased, making theinformation provided by the marking 9 and the window 8 quicker andeasier for a user to interpret. Moreover, increasing the amount ofrotation of the dial 2 gives the user more accurate control over thetemperature of the soleplate and the amount of steam being produced bythe device.

However, as shown in FIG. 2b , if the angular separation between theintermediate steam position (indicated by intermediate steam label 5)and the maximum position (indicated by maximum label 7) is increased,and if the size of the window 8 and marking 9 are increased accordingly,then the marking 9 may also be partially visible in the window 8 whenthe dial 2 is set to the minimum position (indicated by the minimumlabel 6). It is preferable to avoid this situation as this may bemisleading and can cause confusion among users.

As shown in FIG. 2b , in this example, the angle X, between the minimumlabel 6 and the maximum label 7 (short direction), is less than theangle Y, between the maximum label 7 and the intermediate steam label 5.This arrangement results in the problem described above, where themarking 9 behind the dial 2 is visible through the window 8 when thedial 2 is in the minimum position, or close to it. To avoid this, angleX can be increased until it is greater than angle Y, but this is lessdesirable because it would require a re-design of the controller beingcontrolled by rotation of the dial 2. Moreover, it is preferable toprovide the dial 2, and the controller, with as much rotational movementas possible (between the minimum and maximum positions) so that the useris able to more accurately control the temperature and/or steam rate ofthe device. Also, this increased rotational distance means that thewindow 8 and the marking 9 are larger and provide the user with moreaccurate and interpretable information on the amount of steam beingproduced.

A further embodiment of the invention is shown in FIGS. 3 to 6 c. Inparticular, FIG. 3 shows a perspective cut-away view of a controlelement 10 for a temperature and steam controller of a steam iron, thecontrol element 10 having a dial 11 and a graphic plate 12. As shown,the dial 11 comprises a circular upper part 13 which is visible on thedevice and which a user can grip to rotate the dial 11. The upper part13 has maximum, minimum and intermediate temperature labels 17, 16, 14that, together with an adjacent pointer (not shown in FIG. 3), allow auser to control the soleplate temperature by rotating the dial 11. Thelabels 17, 16, 14, when aligned with a pointer adjacent to the dial 2,indicate three positions of the dial 11 and the controller: a maximumposition, a minimum position and an intermediate temperature position,respectively. The control element 10 shown in FIG. 3 also comprises aspindle 17 which extends from the dial 11 and is attached to acontroller (not shown) to alter a temperature and/or steamcharacteristic of the steam iron as the dial 11 is rotated. It will beappreciated that, due to the dial 11 being connected to a controller,from the minimum position the dial 11 can only be rotated in onedirection, in this example a clockwise direction. Similarly, when thedial 11 is set to the maximum position, the dial 11 can only be rotatedin an anti-clockwise direction. In other words, the dial 11 can only berotated in the larger angular region between the minimum and maximumpositions, and cannot be rotated into the smaller angular region.

Also shown in FIG. 3, similarly to the dial described with reference toFIG. 2a , the control element 10 has an intermediate steam positionwhich indicates at which point the steam iron may begin to generatesteam as the dial 11 is rotated towards the maximum label 17. Forpurposes of clarity, the intermediate steam position is indicated byintermediate steam label 15, although it will be appreciated that theintermediate steam label 15 is optional and provided for the purpose ofclarity.

As shown in FIG. 3, the dial 11 also has a window 18 which is formed inan arcuate shape in the upper part 13 of the dial 11. The window 18 isprovided so that one or more markings (not shown in FIG. 3) on thegraphic plate 12 are visible through the window 18 during a firstangular range of the rotation of the dial 11, in the same way as theembodiment described with reference to FIG. 2 a.

In this example, the window 18 has an arcuate shape and extends aroundthe dial 11 between the intermediate steam label 15 and the maximumlabel 17. However, it will be appreciated that the window 18 may beformed by any shape opening, or several openings, in the dial 11 thatallows a user to view the graphic plate 12 disposed behind the dial 11.Furthermore, the window 18 may extend to the circumferential edge of thedial 11.

When the dial 11 is rotated to the intermediate steam position thepointer (not shown in FIG. 3) will be approximately aligned with an endof the window 18 and an end of the marking (not shown in FIG. 3) on thegraphic plate 12 will be visible in the window 18. Therefore, anadditional intermediate steam label 15 is not essential.

The graphic plate 12 is rotatably mounted to the spindle or to the dialsuch that it can rotate independently of the dial 11, within the limitsdefined by the engagement means and biasing means described hereinafterwith reference to FIGS. 4a to 6c . The graphic plate 12 is rotatablymounted to either the spindle 17 or a spigot of the dial 11 or, as shownin FIG. 3, the graphic plate 11 may be received within a cylindricalwall 20 that extends from the dial 11 and surrounds the graphic plate12.

FIGS. 4a to 4c show schematic drawings of the control element 10 of FIG.3 in the minimum, intermediate steam, and maximum positions indicated bythe labels (16, 15, 17, see FIG. 3) on the dial 11. The schematicdrawings are looking from above the control element 10, from the topside of the dial 11, and each of FIGS. 4a, 4b and 4c show the graphicplate 12 and the spindle 17 and features of the dial 11, although, forpurposes of clarity, the upper part (13, see FIG. 3) of the dial 11 isnot shown.

As shown in FIGS. 4a to 4c , the graphic plate 12 comprises a bore 21and an annular gap 22 is formed between the bore 21 of the graphic plate12 and the spindle 17 of the dial 11. A catch 23 extends from the edgeof the bore 21 of the graphic plate 12 into the annular gap 22 in aposition which is approximately aligned with a first end 24 of themarking 19 on the graphic plate 12. A protrusion 25 extends from thedial 11 into the annular gap 22 and is configured to engage with thecatch 23 when the dial 11 is rotated towards the minimum position shownin FIG. 4a . The catch 23 and the protrusion 25 form a first engagementmeans.

The graphic plate 12 also comprises a biasing means (not shown in FIGS.4a to 4c ), which will be described with reference to FIGS. 5a and 5b ,that acts to bias the rotation of the graphic plate 12 towards a homeposition in which the graphic plate 12 is in position to indicate thelevel of steam that will be produced once the dial 11 is rotated beyondthe intermediate steam position (indicated by intermediate steam label15 shown in FIG. 3) towards the maximum position. This home position ofthe graphic plate 12 is shown in FIGS. 4b and 4c . In the home position,the second end 26 of the marking 19 on the graphic plate 12 is alignedwith the pointer 27, such that when the dial 12 is in the intermediatesteam position (indicated by intermediate steam label 15 shown in FIG.3) the second end 29 of the window 18 is aligned with the pointer 27 andthe second end 26 of marking 19 will begin to be visible through thewindow 18. FIGS. 4a to 4c also show the window 18 in the dial 11 and itcan be seen that a first end 28 of the window 18 is proximate to theprotrusion 25 of the dial 11, with the window 18 extending towards asecond end 29 in an arcuate shape. In particular, in this example, thewindow 18 extends between the intermediate steam label (15, see FIG. 3)and the maximum label (17, see FIG. 3) on the dial 11.

FIG. 4a shows the control element 10 when the dial 11 is in the minimumposition, as indicated by the minimum label (16, see FIG. 3) beingaligned with the pointer 27. As shown in FIG. 4a , in this position theprotrusion 25 of the dial 11 has pushed the graphic plate 12 such thatit has rotated to avoid alignment between the marking 19 and window 18,overcoming the previously described situation of misleading alignmentbetween the window 18 and the marking 19. In this example, theprotrusion 25 would have engaged the catch 23 as the dial 11 was rotatedin an anti-clockwise direction towards the minimum position.

Also shown in FIG. 4a , the control element 10 comprises a secondengagement means that limits the extent of rotation of the graphic plate12. As shown, the bore 21 of the graphic plate 12 comprises a recess 30that extends in a circumferential direction around the bore 21 such thatfirst and second ends 31, 32 of the recess are formed with an angularseparation. In this example, the first end 31 of the recess 30 isproximately aligned with the second end 26 of the marking 19, with therecess 30 extending around the graphic plate 12 in the same direction asthe marking 19.

A pin 33 extends into the recess 30 and the pin 33 is attached to, orextends from, a rotatably fixed part of the control element 10. Forexample, the pin 33 may extend from the housing surrounding the controlelement 10. Therefore, the position of the pin 33 is fixed. The firstend 31 of the recess 30 defines the maximum extent of rotation of thegraphic plate 12 in one direction, in this case a clockwise direction,as shown in FIGS. 4b and 4c . The previously mentioned biasing means,described hereinafter with reference to FIGS. 5a and 5b , pushes thegraphic plate 12 into a position where the pin 33 engages the first end31 of the recess 30. This is the home position of the graphic plate12—the position the graphic plate 12 will return to when the protrusion25 is not engaged with the catch 23 to displace the graphic plate 12.

In an alternative embodiment, the recess 30 may be formed by a pair ofspaced protrusions (not shown) on the edge of the bore 21 of the graphicplate 12. In this way, the pin 33 will move between the protrusions,which define the rotational freedom of the graphic plate 12. In analternative embodiment, the recess 30 may be formed on a fixed part ofthe control element 10 or device and the pin 33 may extend from thegraphic plate 12.

The second end 32 of the recess defines the maximum extent of rotationof the graphic plate 12 and the dial 11 in the second direction, in thisexample an anti-clockwise direction, when the protrusion 25 of the dial11 has pushed the graphic plate 12 to rotate into the position shown inFIG. 4a —the minimum position (indicated by label 16, see FIG. 3).Furthermore, the engagement between the pin 33 and the second end 32 ofthe recess, in the position shown in FIG. 4a , also limits the rotationof the dial 11 in this direction.

When the dial 11 is rotated in a clockwise direction towards the maximumposition (indicated by maximum label 17, see FIG. 3) the control element10 will reach the intermediate steam position (indicated by intermediatesteam label 15 shown in FIG. 3) and at that point the second end 26 ofthe marking 19 on the graphic plate 12 will begin to be visible in thesecond end 29 of the window 18, as shown in FIG. 4b . In this position,the biasing means has rotated the graphic plate 12 back to the homeposition, such that the pin 33 has engaged the first end 31 of therecess 30 and the second end 26 of the marking 19 is aligned with thepointer 27.

FIG. 4c shows the control element 10 in the maximum position, asindicated by the maximum label (17, see FIG. 3) being aligned with thepointer 27. As shown in FIG. 4c , when the dial 11 is rotated furtherthan the intermediate steam position (shown in FIG. 4b ), clockwisetowards the maximum position, the marking 19 will occupy more of thewindow 18 until the maximum position is reached, at which point thewindow 18 and marking 19 are fully aligned, as shown in FIG. 4 c.

Therefore, the window 18 and marking 19 are only (at least partially)aligned when the dial 11 is rotated between the intermediate steamposition (shown in FIG. 4b ) and the maximum position (shown in FIG. 4c). Then, as the dial 11 is rotated in an anti-clockwise directiontowards the minimum position (shown in FIG. 4a ) the first engagementmeans (protrusion 25 and catch 23) causes the graphic plate 12 to rotatewith the dial 11, preventing misleading alignment between the marking 19and the window 18 when the dial 11 is set proximate to the minimumposition, as described with reference to FIG. 2 b.

It will be appreciated that, in some embodiments, the clockwise andanti-clockwise rotational directions described above may be reversed.

FIGS. 5a and 5b show the graphic plate 12 in more detail. As describedwith reference to FIGS. 4a to 4c , and shown in FIGS. 5a and 5b , thegraphic plate 12 comprises a bore 21 which includes a catch 23 that,together with a protrusion (25, see FIGS. 4a to 4c ) of the dial (11,see FIGS. 4a to 4c ) forms a first engagement means for rotating thegraphic plate 12 when the dial (11, see FIGS. 4a to 4c ) is rotatedtowards the minimum position (shown in FIG. 4a ). The recess 30 of thegraphic plate 12 is also shown in FIGS. 5a and 5b . As previouslydescribed, the recess 30 is formed on the edge of the bore 21 andengages with a fixed pin (33, see FIGS. 4a to 4c ) to define therotational freedom of the graphic plate 12 the graphic plate 12 can onlybe rotated by the angle defined by the recess 30.

Also shown in FIGS. 5a and 5b , the graphic plate 12 comprises a biasingmeans that urges the graphic plate 12 to rotate towards the homeposition shown in FIGS. 4b and 4c . The biasing means acts against theforce of the protrusion (25, see FIGS. 4a to 4c ) of the dial (11, seeFIGS. 4a to 4c ) which pushes against the catch 23 on the graphic plate12. The biasing means comprises an inclined cam surface 34 formed by aramp shaped cam member 35 that extends from one side of the graphicplate 12 in an axial direction relative to the rotational axis of thegraphic plate 12. As shown in FIG. 5b , a resilient member 36 isdisposed to engage with, and push against, the inclined cam surface 34.In this example, the inclined cam surface 34 of the cam member 35 isinclined such that the distance between the graphic plate 12 and theinclined cam surface 34 increases in one direction around the graphicplate 12, such that when the graphic plate 12 is rotated the resilientmember 36 is compressed and provides a rotational force in the oppositedirection to oppose the displacement of the graphic plate 12 from thehome position shown in FIGS. 4b and 4 c.

The resilient member 36 of the biasing means comprises a pusher 37 and aspring 38 disposed between the pusher 37 and a fixed part of the device,for example a part of the housing of the device. The spring 38 andpusher 37 may be disposed in a fixed recess (not shown) in the housingso that the position of the resilient member 36 (including the spring 38and the pusher 37) is fixed and does not rotate with the graphic plate12 or dial (11, see FIGS. 4a to 4c ).

In an alternative embodiment, the cam member 35 may be formed on a fixedpart of the device and the resilient member 36 may be disposed on thegraphic plate 12. In an alternative embodiment, the biasing means maycomprise a torsion spring that acts to rotate the graphic plate 12towards the home position shown in FIGS. 4b and 4 c.

As described with reference to FIGS. 4a to 5c , the biasing means willpush the graphic plate 12 to rotate into the home position shown inFIGS. 4b and 4c , where the marking 19 is in a position to align withthe window 18 when the dial 11 reaches the intermediate steam positionshown in FIG. 4b . As previously described, as the dial 11 is rotatedtowards the minimum position shown in FIG. 4a the protrusion 25 of thedial 11 engages the catch 23 of the graphic plate 12 and rotates thegraphic plate 12 against the force of the biasing means. In this way,the rotational position of graphic plate 12 is changed when the dial 11is rotated towards the minimum position, to avoid undesired alignmentbetween the window and the indicative marking.

In an alternative embodiment, the first engagement means may be aratchet mechanism (not shown) mounted in between the dial and thegraphic plate that causes the graphic plate to rotate together with thedial when the dial is moved towards the minimum position, to preventalignment between the window and the marking. Then, as the dial isrotated in the opposite direction, towards the intermediate steamposition, the ratchet mechanism disengages and the graphic plate returnsto the home position under the force of a biasing means or being pushedby the ratchet mechanism.

FIGS. 6a to 6c show the operation of the control element 10 describedwith reference to FIGS. 3 to 5 b. FIG. 6a shows the control element 10in the minimum position where the graphic plate 12 has been rotated suchthat the marking (19, see FIGS. 4a to 5c ) on the graphic plate 12 isnot visible through the window 18 in the dial 11. FIG. 6b shows the dial11 in the intermediate steam position and in this position the graphicplate 12 has returned to its home position and the second end 26 of themarking 19 is visible through the window 18 in the dial 11. Therotational position shown in FIG. 6b represents the lowest temperatureat which steam is produced, so the second end 26 of the marking 19 ispartially visible at the second end 29 of the window 18. FIG. 6c showsthe dial 11 rotated to the maximum position in which the marking 19 onthe graphic plate 12 occupies the entire window 18 in the dial 11,indicating that the steam iron is operating at maximum steam rate.

The control element 10 described with reference to FIGS. 3 to 6 c isconfigured such that, during rotation between the maximum position(shown in FIGS. 4c and 6c ) and the intermediate steam position (shownin FIGS. 4b and 6b ) the graphic plate 12 is in the home position andthe dial 11 rotates independently of the graphic plate 12. Furthermore,when the dial is rotated between the minimum position (shown in FIGS. 4aand 6a ) and a (second) intermediate steam position the protrusion 25engages the catch 23 and the graphic plate 12 rotates together with thedial 11 such that the marking 19 and the window 18 are not aligned. Thatis, when the dial 11 is rotated within a first angular range the marking19 on the graphic plate 12 is aligned with the window 18 and the dial 11moves independently of the graphic plate 12 and, in a second angularrange the first engagement means (protrusion 25 and catch 23) causes thegraphic plate 12 to rotate with the dial 11, thereby avoiding undesiredalignment between the window 18 and the marking 19. In this example, athird angular range exists in between the first and second angularranges. When the dial 11 is within this third angular range theengagement means is not engaged, so that the graphic plate 12 does notrotate together with the dial 11, but also the marking 19 and the window18 are not aligned. It will be appreciated that this third angular rangeis optional and, depending on the size of the window 18 and marking 19,the first and second angular ranges may be adjacent to each other withno third angular range therebetween.

The control element 10 described with reference to FIGS. 2a to 6c can berotated between a maximum temperature position (see FIGS. 4c and 6c )and a minimum temperature position (see FIGS. 4a and 6a ) which alsodetermines the amount of steam that the steam iron produces, asindicated by the marking and the window. However, it will be appreciatedthat a similar control element may be used for other controllers, forexample a controller for an air conditioning unit or heater. In thiscase, the marking and the window may combine to indicate some othercharacteristic, for example temperature and/or humidity and/or operatingtime and/or pressure. Alternatively, the control element may be used toselect an operating condition, for example a control element for awashing machine or laundry dryer. It will also be appreciated that thedial may be provided with any labels appropriate for the control elementand the window and marking may indicate a different characteristic tothe labels on the dial. In the examples described with reference toFIGS. 2a to 6c , the control element is used to control both atemperature controller and a steam controller. However, it will beappreciated that the control element may be used to control a singlecontroller, such as steam, temperature, time, humidity etc. In thiscase, the dial may be provided with fewer labels and markings, asappropriate.

Moreover, the window and marking may be positioned elsewhere around thedial, for example between the minimum position and an intermediateposition. The engagement means can also be moved into differentpositions around the control element and dial, depending on therequirement of the thermostat. In some cases, the first and secondengagement means may be configured to engage and rotate the graphicplate as the dial is rotated towards the maximum position. Theengagement means may be arranged to engage the graphic plate as the dialis rotated in a clockwise direction or an anti-clockwise direction. Thebiasing means can also be arranged to oppose either clockwise oranti-clockwise rotation.

It will be appreciated that the term “comprising” does not exclude otherelements or steps and that the indefinite article “a” or “an” does notexclude a plurality. The mere fact that certain measures are recited inmutually different dependent claims does not indicate that a combinationof these measures cannot be used to an advantage. Any reference signs inthe claims should not be construed as limiting the scope of the claims.

Although claims have been formulated in this application to particularcombinations of features, it should be understood that the scope of thedisclosure of the present invention also includes any novel features orany novel combinations of features disclosed herein either explicitly orimplicitly or any generalization thereof, whether or not it relates tothe same invention as presently claimed in any claim and whether or notit mitigates any or all of the same technical problems as does theparent invention. The applicants hereby give notice that new claims maybe formulated to such features and/or combinations of features duringthe prosecution of the present application or of any further applicationderived therefrom.

The invention claimed is:
 1. A control element comprising a dial and agraphic plate located behind the dial, the graphic plate having amarking, wherein the dial has an opening and the marking of the graphicplate is at least partially aligned with the opening so that it isvisible therethrough when the dial is rotated relative to the graphicplate within a first angular range, wherein the graphic plate isrotatably mounted and the control element further comprises engagementmeans operable to cause the dial and the graphic plate to cooperate sothat they rotate together when the dial is rotated within a secondangular range, thereby preventing alignment of the marking on thegraphic plate with the opening in the second angular range so that themarking is not visible through the opening in the second angular range.2. The control element of claim 1, wherein the engagement meanscomprises a protrusion and a catch, the protrusion being arranged toabut the catch when the dial is within the second angular range so thatthe graphic plate rotates together with the dial.
 3. The control elementof claim 2, wherein the protrusion extends from the dial and the catchis formed on the graphic plate.
 4. The control element of claim 1,wherein the engagement means is operable to rotate the graphic platebetween a home position, which is a position occupied by the graphicplate when the dial is rotated within the first angular range, and anend position during rotation of the dial within the second angularrange.
 5. The control element of claim 4, wherein the control elementcomprises biasing means to bias the graphic plate towards the homeposition.
 6. The control element of claim 5, wherein the biasing meanscomprises an inclined cam surface and a resilient member arranged topush against the inclined cam surface.
 7. The control element of claim4, further comprising a second engagement means operable to engage thegraphic plate when the graphic plate is positioned in the home positionand in the end position.
 8. The control element of claim 7, wherein thesecond engagement means comprises a recess in the graphic plate and apin that extends into the recess, the pin engaging with a first end ofthe recess when the graphic plate is rotated to the home position and asecond end of the recess when the graphic plate is rotated to the endposition.
 9. A temperature controller comprising the control element ofclaim 1.